DE102014014133A1 - Workpiece carrier - Google Patents

Abstract

The invention relates to a workpiece carrier for a workpiece conveyor for transporting in particular heavy workpieces with a conveyor chain for conveying the workpiece carrier by transfer of frictional forces and with a guide track for guiding and supporting the conveyor chain and the workpiece carrier, wherein the conveyor chain runs in a U-shaped guideway wherein in addition to the U-shaped guideway support surfaces extend, on which support the workpiece carrier with guide rollers, wherein the workpiece carriers are equipped with a front and a rear carriage, which are provided with a driver for engaging in the U-shaped recess, and wherein the driver over a foot with adjustable contact pressure to overcome the sliding friction are executed, according to the invention a display for visualization of the set contact force is used.

Description

The invention relates to a workpiece carrier for a workpiece conveyor for transporting preferably heavy workpieces.

There are basically two different systems for conveying workpieces by means of workpiece carriers. In one system, the workpiece carriers are connected at fixed intervals to the conveyor belt. The conveyor belt is moved on clocked and thus moves the workpiece carrier from one position to the next. The disadvantage of this is that the timing must be based on the longest lasting process in time and that no input or discharge of workpiece carriers can be done.

In the other system, the conveyor chain runs continuously and the workpiece carriers are taken from the conveyor chain by means of frictional engagement or, before processing points, the workpiece carriers are stopped by external stops and singles. About turnouts and infeed and Ausschleuseinrichtungen the workpiece carriers can be redirected in secondary tracks.

Before a processing or transfer point, the workpiece carriers pile up in certain situations. The frictional forces acting on the chain create high loads on the chain, which must be taken into account when designing them. In addition, caused by the constant friction a significant wear on the chain and the carriers of the workpiece carrier. In order to minimize wear and to make the chain as large as absolutely necessary, it is attempted to keep the friction force as small as possible. There are different approaches especially for heavy workpieces.

A workpiece conveyor for heavy workpieces with a plurality of workpiece carriers is from the EP 0 203 898 known. The workpiece carriers consist of a workpiece carrier for receiving the workpieces and in each case a rotatable front and rear guide segment, which establishes a connection by means of sliding block with the strip arranged thereunder. By means of the friction force, the workpiece carriers are taken from the belt. The adjustment of the contact pressure for the shoe is done by selecting a suitable spring or in addition or alternatively by inferior suitable discs, the biasing force of the spring is adjusted accordingly. In this design, the contact pressure is designed and set once and can not be variably adapted to the current requirements.

The DE 201 21 809 U1 describes a curved, low-build accumulating conveyor with a trolley. In the center of the trolley, an adjustable driver is arranged on the underside, which receives in its interior a pressed by a spring down friction element, which is pressed against the surface of the pallet belt conveyor and thus entrains the trolley. The contact pressure is applied by means of a compression spring which acts on the friction element. Their contact pressure is adjustable via a screw. The contact pressure is set so that the friction is sufficient in each case to move the trolley together with the overlying load by means of the frictional engagement between the friction element and pallet belt conveyor forward. The trolley itself rolls off with four individual castors on the conveyor belt.

A disadvantage of this embodiment is that each individual carrier of a trolley must be set individually. Since there is no indication of the set force, this is a very time consuming process. Whether the contact force for driving is sufficient, must be tested on each trolley individually by experiments. The user will therefore be inclined to ensure in any case that the contact pressure is sufficient. Therefore, there is a risk that, for safety's sake, working with too high contact forces to ensure safe entrainment in any case. However, this is then at the expense of wear of the chain and the workpiece carrier driver. If the accumulation conveyor is retrofitted more frequently and different workpieces and thus differently heavy transport vehicles are used, this requires in each case a time-consuming conversion process.

Object of the present invention is therefore to provide an adjustment mechanism for the contact force between drivers and band, with a simple way to easily adapt to different workpiece weights for a plurality of workpiece carriers can be done and with a once-defined value can be set reproducible again can -. B. in the case of a workpiece change.

If this setting value is determined once, then it can also be stored for certain workpiece / workpiece carrier combinations or noted on the workpiece carrier, for example, and is thus available again as the preset setting value during the next changeover process. If after some time the workpiece carrier and the chain have a certain amount of wear, the setting values can be corrected in a targeted manner, without the need for time-consuming testing and readjustment work on each individual workpiece carrier.

This object is achieved by an adjusting device for the contact pressure according to the features of claim 1.

Further advantageous embodiments are the subject of subsequent to the main claim dependent claims.

Workpiece transport devices, as they are based on the invention, are transport devices in which the workpiece carriers are taken by means of friction by a transport chain. The transport chain often runs in a U-shaped recess in the middle of a band main body, driven by one or more electric motors. The workpiece carriers usually have two guide feet, which stand up in the U-shaped recess on the chain, so that the transport chain can take the workpiece carrier by means of friction. On the workpiece carriers workpiece holders are mounted which are usually designed individually for the workpieces to be transported. In addition, the workpiece carriers, as well as the chain, are guided laterally in the recess.

Before a processing station one or more workpiece carriers are dammed in which is prevented by a stop and or singler of one of the guide feet of the foremost workpiece carrier in its forward movement, by a swing stop. The belt continues to run continuously under the workpiece carrier. If the stop or the singler is opened again, the transport chain takes the dammed workpiece carriers again until the stop or the singler is closed again.

The fact that the workpiece carriers rest loosely on the belt, they can, if necessary, discharged at entry and exit points from the direct part of flow and transported to separate processing stations. At the processing station, the workpiece carrier together with the workpieces arranged thereon can be lifted by a separate lifting station for transferring the workpieces to a processing device, so that the workpiece can be lifted off the workpiece holder and processed. After machining, the workpiece can be put back on this workpiece holder. Depending on the process sequence, the workpiece can also be stored on a later arriving empty workpiece carrier.

For heavy workpieces, it is attempted to design the transport system for the workpieces in such a way that significant parts of the workpiece weight are taken up by additional rollers on the workpiece carriers. These rollers run on the band main body or on special rails next to the band main body.

In contrast to small workpieces, in which the entire weight of the workpiece and workpiece carriers on the chain loads, the possibility in the embodiment of the invention by the distribution of forces to size the conveyor belt / transport chain smaller, because they only need the power for Overcoming the rolling friction apply which is necessary to move the workpiece carriers along the conveyor track on rollers. In addition, the contact pressure acting on the chain, and which is necessary so that the workpiece carriers are taken from the chain, be made adjustable.

To apply this contact force adjustable on the tape, there are several possibilities. The simplest of these is certainly the means of a spring whose travel is variable variable by means of mechanical elements. In the embodiment according to the invention, a setting device is added to the adjusting device by means of which a characteristic value for the set spring force can be visualized. This may be a display which, for example, depicts the linear displacement of the spring chamber, but could also be a pressure indicator indicating the actual contact pressure. It is important, above all, that the display provides reproducible characteristic values for the set contact force, so that, for example, the required force for carrying the workpiece carrier can be determined on a workpiece carrier. This is then transferred by transferring the set and determined characteristics to the other workpiece carriers on the transport device.

Is after a certain period of use of the device a certain wear on the chain and the drivers achieved, the contact pressure can be adjusted relatively easily by the new set value is determined on a workpiece carrier and this can then be easily transferred to the other workpiece carriers.

If different workpiece types are conveyed by one and the same transport device, the workpiece carriers can also be adjusted to different contact pressures. By visualizing the set values, the user can then check immediately whether the correct values have been set for the current workpiece type.

This could, if necessary even be done via an external control device, especially if the workpiece carrier with an individual marking or a workpiece carrier identification device such as an RFID or a data carrier. This would require an optical evaluation of the display or an electronic data transmission of the set values. This would be especially interesting if the transport device over long distances within a factory automation for linking a variety of machines runs. For a simple machine automation a simple visualization is certainly sufficient.

In a further embodiment of the invention, the display device is protected by a protective cover against inadvertent adjustment. This can be prevented that the contact force is unintentionally adjusted when handling the workpiece carrier or workpieces on and with the carriers. Furthermore, the adjusting device and in particular its display device is protected from damage.

Next, it would be possible to perform the protective cover so that it additionally prevents an unintentional adjustment of the contact force by the cover achieves a blockade of the adjustment movement in a certain position. This could be achieved by a mechanical blocking device that engages in or at one or more recesses or surfaces on the adjuster. Furthermore, a clamping function that exerts the protective device on the adjustment would be possible.

To adjust the adjustment, the guard can release by lifting, tilting, moving or twisting the adjustment, so that it can be adjusted. After adjustment, the adjustment can then be blocked by a reverse movement.

Further features, details and advantages of the invention are explained in more detail below with reference to several drawings. Show it:

1 FIG. 2: a side view of a conveying device according to the invention with a plurality of workpiece carriers, FIG.

2 : a perspective view of a plurality of workpiece carriers according to the invention,

3 a section through a workpiece carrier in the region of the driver,

4 a detailed view of a workpiece carrier with the adjustment and a protective cover.

5 a detailed view of a workpiece carrier with an adjustment and display device

1 shows a side view of a conveying device with a plurality of workpiece carriers, which are consecutive on a jam line. The workpiece carriers 10 with the front and rear carriage 43a . 43b run with their roles 41 on rails 42 , the side of a tape main body 40 are mounted. The carriages 43 are designed as a pivot axis similar to a turntable steering and guided in the middle in the band main body. The rails, which essentially take up the workpiece weight, are via clamping pieces 45 with the band main body 40 connected and can be easily replaced when wear occurs.

With the identification device attached to the carriage 18 For example, the workpiece carriers can be detected by means of a suitable identification device and, depending on the stored information, certain operations can be initiated at different points of the conveyor. The identification can, for example, optically over certain codes z. As data matrix code, barcode, etc. or by reading stored information from storage such as RFID, transponders, etc. take place. This is also a chaotic production with different workpiece types on a conveyor line possible.

In the perspective view of the conveyor line in 2 Further features of the device according to the invention are shown. With the adjustment device 38 for the contact pressure with integrated display 34 The contact pressure with which the carriers are pressed against the belt can be set individually and also checked very easily. So that the set contact pressure does not change, is in the protective cover 37 an adjustment 37a integrated. The workpieces which are conveyed by means of this workpiece carrier, can by means of simple Werkstückaufnahmepins 17 . 17 ' or by consuming and thus heavier special workpiece recordings are taken from the workpiece carriers. These workpiece holders influence the respective weight of the workpiece carrier and must be taken into account when setting the frictional force. For empty workpiece carriers, these drive exclusively with the drivers on the chain conveyor and not with the rollers 41 on the side rails 42 to reduce wear. But so that the contact pressure must be adjusted individually to the weight of the workpiece carrier, which in turn requires a quick and easy adjustment. If different workpiece types are conveyed on a belt in a chaotic sequence, each workpiece carrier must be set individually or the set contact force must be easily checked. This can be an individual marking 12 the individual workpiece carrier be helpful.

The distance between the workpiece carriers to each other via spacers 47 . 47a respected. In between is an annular buffer 46 mounted from elastic material, which deforms when mounting several workpiece carriers in a row so that it rests against the side walls of the chain guide and so at least partially transfers the dynamic pressure due to the workpiece carrier jam on the lateral guide walls. Thus, not the entire dynamic pressure of the dammed workpiece carrier on the stop or singler is the cause of the workpiece carrier jam. Furthermore, the elastic ring acts as a shock absorber for the incoming workpiece carriers. This will mitigate the impact that would otherwise be caused by the workpiece carrier approaching the jam end.

The 3 shows a section through a carriage 43 a erfindungsmäßen workpiece carrier in the region of the driver 35 , Laterally in the band main body 40 become the carriages 43 with the guide rollers 44 in the U-shaped recess in which also the band 20 running. Via laterally mounted clamping pieces 45 are the running tracks 42 mounted on the band main body. On these run the carriage 43 with their casters 41 and thus substantially support the workpiece weight on the tape base. The ribbon 20 is loaded only with the contact pressure on the means of the driver, the workpiece carriers are transported.

About a spring 39 that will be in the driver 35 guided foot section 30 against the band 20 Pressed and takes over the friction with the workpiece transport device in the belt conveying direction. The contact pressure of the spring 39 is about the, adjustment device 38 with display 34 with the help of the pestle 36 applied. By vertical adjustment of the ram 36 down the installation space of the spring is limited and so we increased the contact pressure. At the same time changes by the rotation of the adjustment, the above mounted in the lid of the adjustment display 34 and thus provides a reference value for the set contact force. This value can be transferred to the other drivers by the adjusting device is rotated so long until this value is reached. Thus, the same contact pressure is set in these drivers. The way in which this force is adjusted, but depends on the mechanical structure of the adjustment 38 from. Just as well here can be moved a hydraulic piston and thus increase the contact pressure of the spring. As a reference value in this case the hydraulic pressure in the adjustment system could be used.

Laterally on the band main body 40 Here is the reading unit 19 for evaluating the data of the (workpiece carrier) identification device 18 recognizable. On the workpiece carriers are the workpiece supports 11 , in this case in a version as recording pins 17 executed, mounted.

In 4 shows again a detailed view of a carriage of a workpiece carrier. Here is an embodiment of an adjustment 37a which are in the protective cover 37 for the adjustment device 38 is integrated for the contact pressure shown. The sliding in the direction of arrow protective cover engages laterally in recesses on twist knob of the adjustment 38 and thus prevents unwanted adjustment of the contact pressure. However, the design of the adjustment depends heavily on how the contact pressure is adjusted (twisting, shifting, etc.) and is shown here only as an example.

In 5 is in the detail view of a workpiece carrier again especially the display device 34 shown - here as a digital display of a numerical value.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0203898 [0005]
• DE 20121809 U1 [0006]

Claims (11)

Workpiece carrier for a workpiece conveyor for transporting in particular heavy workpieces with a conveyor chain for conveying the workpiece carrier by transfer of frictional forces and with a guideway for guiding and supporting the conveyor chain and the workpiece carrier, wherein the conveyor chain extends in a U-shaped guideway, wherein adjacent to the U-shaped guideway support surfaces on which support the workpiece carrier with guide rollers, wherein the workpiece carriers are equipped with a front and a rear carriage, which are provided with a driver for engaging in the U-shaped recess, and wherein the driver via a Foot part with adjustable contact pressure to overcome the sliding friction are executed, characterized in that the adjustable driver with foot has a display for visualization of the set contact force. Workpiece carrier for a workpiece conveyor device according to claim 1, characterized in that the display device for the contact force in the driver indicates a value for a set path, a set force or a set pressure. Workpiece carrier for a workpiece conveyor device according to claim 1 or 2, characterized in that the adjusting device, for adjusting the contact force for the driver, is equipped with a protective cover which prevents unintentional adjustment of the contact pressure and protects the adjustment from damage. Workpiece carrier for a workpiece conveyor device according to claim 1 to 3, characterized in that the adjusting device for adjusting the contact force for the driver is equipped with a protective cover and in the protective cover a blocking and / or clamping device is integrated, which prevents unintentional adjustment of the contact pressure , Workpiece carrier for a workpiece conveyor device according to claim 3 or 4, characterized in that the adjusting device, for adjusting the contact force for the driver, is equipped with a protective cover and a quick change, which allows a tool-free removal, displacement, rotation or tilting of the protective device, so that the adjusting device is time-saving adjustable to a new value. Workpiece carrier for a workpiece conveyor device according to one of the preceding claims, characterized in that the workpiece carriers are equipped with a workpiece carrier identification device, with which the carriers are uniquely identifiable, whereby it is possible that workpiece carrier with different workpiece types and different driver contact pressure on a workpiece conveyor be promoted together. Method for setting a plurality of workpiece carriers according to one of the preceding claims for a workpiece conveyor, characterized in that the contact force determined on a workpiece carrier can be easily transferred to the other workpiece carrier by the read from the display value is also set in the other workpiece carriers. Method for setting a plurality of workpiece holders according to one of the preceding claims for a workpiece conveyor, characterized in that the contact pressure can be adjusted simply by the fact that the adjusting device is actuated until the value of the display corresponds to a predetermined value. Method for setting a plurality of workpiece carriers according to one of the preceding claims for a workpiece conveyor, characterized in that the set contact pressure can be easily checked by a visual inspection of the display for correctness. Method for setting a plurality of workpiece carriers according to one of the preceding claims for a workpiece conveyor, characterized in that the contact force can be adjusted by wear-related reduction of Reibmitnahmekraft simply by the adjustment is corrected at all workpiece carriers by a predefined value. Workpiece conveyor for the use of workpiece carriers according to one of the preceding claims, characterized in that the workpiece carriers are used with differently adjusted contact pressure for conveying different types of workpieces on a workpiece conveyor.

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